Pick some good change from #150074, thanks

Mel-Chen · preames · Mel-Chen · commit 4688b4cc6eff · 2025-07-24T02:58:26.000-07:00
Co-authored-by: Philip Reames &lt;preames@rivosinc.com&gt;
diff --git a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
@@ -979,10 +979,13 @@ InstructionCost RISCVTTIImpl::getInterleavedMemoryOpCost(
     Align Alignment, unsigned AddressSpace, TTI::TargetCostKind CostKind,
     bool UseMaskForCond, bool UseMaskForGaps) const {
 
-  // The interleaved memory access pass will lower interleaved memory ops (i.e
-  // a load and store followed by a specific shuffle) to vlseg/vsseg
-  // intrinsics.
-  if (!UseMaskForGaps && Factor <= TLI->getMaxSupportedInterleaveFactor()) {
+  // The interleaved memory access pass will lower (de)interleave ops combined
+  // with an adjacent appropriate memory to vlseg/vsseg intrinsics. vlseg/vsseg
+  // only support masking per-iteration (i.e. condition), not per-segment (i.e.
+  // gap).
+  // TODO: Support masked interleaved access for fixed length vector.
+  if ((isa<ScalableVectorType>(VecTy) || !UseMaskForCond) && !UseMaskForGaps &&
+      Factor <= TLI->getMaxSupportedInterleaveFactor()) {
     auto *VTy = cast<VectorType>(VecTy);
     std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(VTy);
     // Need to make sure type has't been scalarized
diff --git a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.h
@@ -399,7 +399,7 @@ class RISCVTTIImpl final : public BasicTTIImplBase<RISCVTTIImpl> {
   bool enableInterleavedAccessVectorization() const override { return true; }
 
   bool enableMaskedInterleavedAccessVectorization() const override {
-    return true;
+    return ST->hasVInstructions();
   }
 
   unsigned getMinTripCountTailFoldingThreshold() const override;

Original file line number	Diff line number	Diff line change
`@@ -399,7 +399,7 @@ class RISCVTTIImpl final : public BasicTTIImplBase<RISCVTTIImpl> {`
`399`	`399`	`bool enableInterleavedAccessVectorization() const override { return true; }`
`400`	`400`
`401`	`401`	`bool enableMaskedInterleavedAccessVectorization() const override {`
`402`		`- return true;`
	`402`	`+ return ST->hasVInstructions();`
`403`	`403`	`}`
`404`	`404`
`405`	`405`	`unsigned getMinTripCountTailFoldingThreshold() const override;`